/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.core;

import java.util.HashMap;
import java.util.Map;

/**
 * @author apr@cs.com.uy
 * @version $Id$
 * @since jPOS 1.1
 * <p/>
 * A simple sequencer intended for Debugging applications.<br>
 * Production grade Sequencers are required to be persistent capables
 */
@SuppressWarnings("unchecked")
public class VolatileSequencer implements Sequencer, VolatileSequencerMBean {
	private Map map;

	public VolatileSequencer() {
		map = new HashMap();
	}

	/**
	 * @param counterName
	 * @param add         increment
	 * @return counterName's value + add
	 */
	synchronized public int get(String counterName, int add) {
		int i = 0;
		Integer I = (Integer) map.get(counterName);
		if (I != null)
			i = I;
		i += add;
		map.put(counterName, i);
		return i;
	}

	/**
	 * @param counterName
	 * @return counterName's value + 1
	 */
	public int get(String counterName) {
		return get(counterName, 1);
	}

	/**
	 * @param counterName
	 * @param newValue
	 * @return oldValue
	 */
	synchronized public int set(String counterName, int newValue) {
		int oldValue = 0;
		Integer I = (Integer) map.get(counterName);
		if (I != null)
			oldValue = I;
		map.put(counterName, newValue);
		return oldValue;
	}

	public String[] getCounterNames() {
		Object[] o = map.keySet().toArray();
		String[] s = new String[o.length];
		System.arraycopy(o, 0, s, 0, o.length);
		return s;
	}
}
